/** "Return the total length of the formatted bundle block data." [DTN2] */
public static int total_length(final BlockInfoVec blocks) {
int ret = 0;
Iterator<BlockInfo> itr = blocks.iterator();
while (itr.hasNext()) {
BlockInfo block = itr.next();
ret += block.full_length();
}
return ret;
}
/**
* "Generate contents for the given BlockInfoVec on the given Link." [DTN2]
*
* @return "the total length of the formatted blocks for this bundle." [DTN2]
*/
public static int generate_blocks(Bundle bundle, BlockInfoVec blocks, final Link link) {
// "now assert there's at least 2 blocks (primary + payload) and
// that the primary is first" [DTN2]
assert (blocks.size() >= 2);
assert (blocks.front().type() == bundle_block_type_t.PRIMARY_BLOCK);
// "now we make a pass through the list and call generate on
// each block processor" [DTN2]
for (int i = 0; i < blocks.size(); i++) {
boolean last = i == blocks.size() - 1;
BlockInfo iter = blocks.get(i);
iter.owner().generate(bundle, blocks, iter, link, last);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"generated block (owner %s type %s) "
+ "data_offset %d data_length %d , contents_length %d",
iter.owner().block_type(),
iter.type(),
iter.data_offset(),
iter.data_length(),
iter.contents().position()));
if (last) {
assert ((iter.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) != 0);
} else {
assert ((iter.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) == 0);
}
}
// "Now that all the EID references are added to the dictionary,
// generate the primary block." [DTN2]
PrimaryBlockProcessor pbp =
(PrimaryBlockProcessor) find_processor(BundleProtocol.bundle_block_type_t.PRIMARY_BLOCK);
assert (blocks.front().owner() == pbp);
pbp.generate_primary(bundle, blocks, blocks.front());
// "make a final pass through, calling finalize() and extracting
// the block length" [DTN2]
int total_len = 0;
for (int i = blocks.size() - 1; i >= 0; i--) {
BlockInfo iter = blocks.get(i);
iter.owner().finalize(bundle, blocks, iter, link);
total_len += iter.full_length();
}
return total_len;
}
/**
* "Temporary helper function to find the offset of the first byte of the payload in a
* BlockInfoVec." [DTN2]
*/
public static int payload_offset(final BlockInfoVec blocks) {
int ret = 0;
Iterator<BlockInfo> itr = blocks.iterator();
while (itr.hasNext()) {
BlockInfo block = itr.next();
if (block.type() == BundleProtocol.bundle_block_type_t.PAYLOAD_BLOCK) {
ret += block.data_offset();
return ret;
}
ret += block.full_length();
}
return ret;
}
/**
* "Copies out a chunk of formatted bundle data at a specified offset from the provided
* BlockInfoVec." [DTN2]
*
* @return "the length of the chunk produced (up to the supplied length) and sets last to true if
* the bundle is complete." [DTN2]
*/
public static int produce(
final Bundle bundle,
final BlockInfoVec blocks,
IByteBuffer data,
int offset,
int len,
boolean[] last) {
int old_position = data.position();
int origlen = len;
last[0] = false;
if (len == 0) return 0;
assert (!blocks.isEmpty());
Iterator<BlockInfo> iter = blocks.iterator();
BlockInfo current_block = iter.next();
// "advance past any blocks that are skipped by the given offset."[DTN2]
while (offset >= current_block.full_length()) {
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce skipping block type %s "
+ "since offset %d >= block length %d",
current_block.type().toString(), offset, current_block.full_length()));
offset -= current_block.full_length();
current_block = iter.next();
}
// "the offset value now should be within the current block" [DTN2]
while (true) {
// The first time remainder will be minus from leftover offset above
// but later on it will be the full content of the block
int remainder = current_block.full_length() - offset;
int tocopy = Math.min(len, remainder);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce copying %d/%d bytes from "
+ "block type %s at offset %d",
tocopy, remainder, current_block.type().toString(), offset));
current_block.owner().produce(bundle, current_block, data, offset, tocopy);
len -= tocopy;
// move the position of IByteBuffer
data.position(data.position() + tocopy);
// "if we've copied out the full amount the user asked for,
// we're done. note that we need to check the corner case
// where we completed the block exactly to properly set the
// last bit" [DTN2]
if (len == 0) {
if ((tocopy == remainder)
&& ((current_block.flags()
& BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode())
> 0)) {
last[0] = true;
}
break;
}
// "we completed the current block, so we're done if this
// is the last block, even if there's space in the user buffer"
// [DTN2]
assert (tocopy == remainder);
if ((current_block.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode())
> 0) {
last[0] = true;
break;
}
// advance to next block
current_block = iter.next();
offset = 0;
}
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce complete: "
+ "produced %d bytes, bundle id %d, status is %s",
origlen - len, bundle.bundleid(), last[0] ? "complete" : "not complete"));
data.position(old_position);
return origlen - len;
}